Portable testing-machine



F. FIGARI.

PORTABLE TESTING MACHINE.

APPLICATION FILED MAR. 21, 1919.

1,332,491. Patented Mar. 2, 1920.

H I Hil -l l nv'eniar -23 r 11 n EFL ama- FRANCESCQ FIGAEI, F GENOAjITALY.

romance sesame-machine.

Specification of Letters Patent.

Application filed March 27, 1919. Serial No. 285,687.

To all whom it may concern:

Be it known t at I, Fnancn'sco FIGARI, a subject of the King of Italy,residing at Genoa, Italy, have invented a new and useful PortableTesting-Machine, of which the following is a specification. I

The invention relates to a portable testing machine in which adifferential screw is employed for exerting strains upon the piecesunder test, these strains being transmitted upon a plate, thedeflections of which being utilized for the n'leasurement of the exertedstrains. a

The invention also refers to a special de vice of registration of thestrains exerted on the plate with utilization of the sustaineddeflections, by which device the indication of the compression as wellasof the tension strains takes place by one graduation and .with oneindicator displaced in one direction only.

The invention is illustrated in a form of execution in the accompanyingdrawing in which: 1

Figure 1 is a front elevation of the machine with a sectional middleview of the pedestal. l v

Fig. 2 is a partial side view of the machine. v

Fig. 3 is a front view of the pedestal of the machine.

' Fig. 4: is a horizontal sectional view according to line AB of Fig. 3and Fig. 5 shows a detail of the machine.

In these figures upon the cross bar 1 fastened with nut and counternutupon the columns 2 of the machine, is arranged the nut 3, which ispenetrated by the two telescopic screws 4 and 5. The inner screws 5 iscoupled with the cross bar (3, which travels by means of its jawed ends,preventing the rotation of this screw, upon the columns 2. The piece tobe tested is fastened with one end within the jaw 7 of the cross bar 6and with the other end within the jaw 7 of the cylindrical body 8 whichbody slidably penetrating the pedestal of the machine, terminates withthe pin 9. Pin 9 passes a hole of the plate 10 and is threaded into thebody 11. The plate 10 is laterally and on the bottom supported by twopins 12 fastened on the pedestal of the machine, while two stops 13 arearranged opposite the pins 12 in contact with the upper surface of theplate. With the plate 10 is connected by the pin 14 the 15 upon the Wallof the pedestal. 15 terminates on its other end with a toothed lever l5,having its fulcrum on the pinlfi.

The pin 18 is arranged on a movable block 17, shaped as a nut 18 in itsupper part and supplied witha screw 15) supported against the wallet thepedestal by supports 20. The

block 17 is supplied with a bolt 21. in its lower part, which allows tofix the position of the block and of the fulcrum of the lover The leversegment 22 engaging with the pinion 23, fastened on the shaft 24. Theshaft 2 on which are keyed the two bevel gears 25 and 25' can bedisplaced axially within the frame 26, so as to permit the engagement ofthe gear 25 or 25 with the bevel gear 27 according as'the machine willbe subjected to compression or tensile strains and this for the purposeto obtain always the same sense of rotation of the gear 27 on its shafton which is fastened the indicator 2S sliding on the graduation 25). Inturning the screw 19 the block 17 is displaced and with it the pin 16and in this mannorthe device of registration may be re ulated beforestarting the machine, or it the substitution of a plate is requisite.

'The parts illustrated in Fig. 1 allow of executing tensile tests on thetest piece fast,

cned within the jaws 7 and 7. During this proceeding the plate 10 isbearing against the stops l3 and pushed in its central part by the block11, deflects toward the top, the tensile strains exerted by the machineand corresponding with these deflections being registered by theindicator 28 and the graduation 29.

For (JOII'IPIOSSlOl). tests the cylindrical body 8 of Fig. 1 issubstituted by the block 8 of Fig. 5, which by its lower rib 30 causesthe deflection of the plate 10 supported on the pins 12, the compressionstrains exerted by i the machine corrcsmndiiw with these dofiectionsbeing registered again by the indicator 28 on-the graduation 29.

The machine is just as well adapted for Brinell tests.

It is understood that there must always exist a difi'crem-e between thepitches of the screws 4 and 5. The smaller this difference is, thebigger is the strain which can bc exerted. According to studies andpractical testsmade by theinvcntor it results that the two pitches ofthe screws 4t and 5 must be very large ones and thus that theinclination of the thread of the driven screw will con- Patented Mai-.2.1920.

stitu-te a bigger angle than the friction angle in order to obtain .agood mechanical workin of the screws. I

' aving thus described my invention, what I claim 1s: I, y

1. A portable testingmachine including a differential screw for theexertion of ten- .sile and compression strains, a plate to which the.strains are transmitted, means for supporting the plate in a horizontalposition and means associatedwith the central part of the plate forregistering thedeflections. of the plate and thereby indicate thetensile and compression strains.

2.- A portable testing machine including a differential screw for theexertion'of tensile and compression strains and having a large pitch anda. small difference between the pitches, a plate to which the strains 7are transmitted, stops engaging the up er and lower surfaces of theplate near t e ends thereof and supporting the plate in, a horizontalposition v and means associated with the central part'of the plate forregistering the deflections of the plate.

3. A portable testing machine comprising a differential screw for theexertion of ten- .sile and compression strains, a plate to "which thestrains are imparted, means associated with the ends-of the plate forsupporting the plate in a horizontal position, a pivota mounted leverone of which is associated with the central part of the plate,

a toothed segment formed on the opposite end of the lever, a rotatablymounted shaft,

I a pinion' carried by the shaft and meshing with the toothed segment,beveled gears carjustably fulerumed t0 thepedestal and hav-; ing one endconnected with the central )art" of the plate, a toothed segment formeon the other-end of the lever," a shaft rotata bly mounted on the pinioncarried by the shaft and arranged in mesh with toothed segment, spacedbeveled gears on the shaft,

a rockably mounted indicator on the pedestal and another gear coupledwith the ind1- cator and designed to be engaged by one of the otherbeveled gears so as to register the deflections of the: plate.

In testimony whereof I have signed my name to this specification in thepresence of two subscribmg witnesses.

. FRANCESCO FIGARI. Witnesses:

Donro DEBER, i WILLIAM P. Sr'rocnnnr.

